Conveyer-spiral.



' W. SGHROER.

coNvEYBB SPIRAL.

APPLICATION FILED KAY 9, 1908.

915.702. Patented Mar.16,19o9.

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l UNITED sirenas` PATENT oFFIoE.

WILHELM scHRoER, or DAHLERBRGK, salama-r.

Vcoliviairan-sentaL.t

Specicationof Letters Patent.

original eppiieetlen'aletl oeteber 9, loos, serlelfne. 389,695. Dividedand tnie epplieetien mea may 9, loos.

Serial No. 431,928.

.To all whom it 'may concern: p

Be it known that I, WILHELM SCHROER', a subject of the King of Prussia,German Emperor, residing at Dahlerbrck, in the Provlnce of Westphalia,Kingdon of Prussia, German Em ire, have invented a certain new` anduseful anllfacture of' Conveyer-Spiral's, of which the following is aspecification.

This invention relates to the manufacture of conveyer spirals.

' A process is already known by which metal p bands are made of aT-section by rolling out metal bars of the breadth of the desired metalband, these bars being notched at the side and then rolled, keepin thebreadth constant, so that a longitudina slot is left in the band; thesides of this slotted art are afterward s layed out and rolle to formthe, finishe section. Suchprofile iron has the advantage of greaterlightness and'cheapness as compared with the ordinaryT-section iron.Moreover byv this simple rocess profile iron can be formed with a hi iistem portion and short arms or flanges, t ese latter being of half thestem thickness, a form which could not be produced by the previouslyknown rolling processes. f

It is the object of the present invention to apply the profile irons orbands in the formation of conveyerspirals for which purpose they arefound to be particularly useful.

' The necessary spiralshape is produced 1n known manner by coihng orrolling the bands and` these latter are then fixed by means of theirflanges on the shaft or on a tube serving as a shaft. In stretching outthe spiral it is usually sufficient to fix only its ends to the shaft,but it is better to effect the fixing at several places besides. 'l

.At the meeting point of twobands no further connection is required, itbeing quite unnecessary to employ connecting plates or ieces attached tothe webs of the spiral.

his is' es ecially of advantage in facilitating thejnterc ange of theparts of a spiral when this becomes worn out, as byl this constructionmuch time and labor is then saved. Further in a conveyer spiral made inthis way there is they great advantage that the. whole spiral has a flatacting surface without any perceptible pro'ecting 'portions so thatthere is very little riction against the material which is being fed bythe spiral. Moreover if the flanges are fixed in position by means ofcountersunk bolts or rivets there l will be no projecting pieces left tobreak the smooth surface of the whole band. Quite apart from otheradvantages of this arrangement there is a saving in work during theoperation of the conveyer, particularly when it is of large siz'e.

It is already known to make conveyer spirals of cast or rolled metalstrips which have a flan e on one side. Conveyer spirals made by'thlsmethod have the disadvantage that, on account 'of having a flange 'onone side only, any pressure on the side 'of the flange would cause abending of the web in the opposite direction. In conveyer spirals madeaccording to the present invention the strips stretch several tlmesaround the axis necessitating'few attachments as com ared with conveyer`-spiral strips made hit erto which -oilly extended for a short distancearound the periphery of the axis. A The accompanying drawingillustratesa Patented Meren 1c, 190e. e

portion of alconveyer made by the present method. A

a is the shaft carrying the spiral band b shown in cross section at c.

"d is a butt joint between 4two consecutive p bands and it is seen thatno connecting plates, are provided between the twoparts. Conveyerspirals formed of bands in this way have not been previously used, butas a rule the web portion of a spiral was formed of.,

flat iron spirals which were attached to the shaft byfangle pieces andthe ends of which were connected one to another' by fish-plateconnections. The disadvantages of this elder ferm ef .spiral will beevient Witheet further statement, from the preceding descri tion of thepresent invention. aving now particularly described and ascertained thenature of my said invention and in what manner the sameis to be pei'-formed, I declare that what I claim is:

A conveyer spiral consisting of a screw blade extending around a shaftfor more than a full pitch and of a spiral base integral therewith andin T-shapeada ted to fit over a shaft', and having only ha f thethickness of that ofthe screw blade.

In testimony whereof I have signed my vname to this specification in thepresence of two subscribing witnesses. e W'. SCHROER.

Witnesses: MYRA E. BUsEY,

BessrE F. DUNLAP.

